Lithium ion batteries, as the preferred energy source of electronic end products, have advantages of high specific energy, high voltage, safe and environmental friendship, long service life, and the like. With the continuous development of the functions of electronic end products, it requires higher criteria for specific energy, safety, and the like of lithium ion batteries. Therefore, the development of higher cost-effective electrode materials is an important topic for a researcher in the art of lithium ion batteries.
At present, LiCoO2 is an active material for positive electrodes commonly used in lithium ion batteries. LiCoO2 is commercialized earlier and the process for preparing LiCoO2 is well-developed. LiCoO2 has relatively stable electrochemical properties, good processing behaviors, high compacted density (3.7 to 3.9 g/cm3), relatively high mass specific capacity (138 to 145 mAh/g), stable structure, good cycle performance (the capacity retention ratio of 88 to 91% after 1 C 300 cycles), high and stable voltage platform (80% of which is more than 3.6 V) and good compatibility with electrolyte solutions. However, LiCoO2 is expansive. The cost of LiCoO2 is higher and higher due to rare resource and continuous rise of LiCoO2 price. The ternary material lithium nickel cobalt manganese oxide has good properties. The composite positive electrode material of the ternary material and LiCoO2 has good cycle performance and volumetric specific capacity. Moreover, batteries using such positive electrode material can support overcharge voltage of about 1 C 4.7 V and have good safety so as to meet the conventional applications. However, the anti-overcharge safety of batteries is required to be improved in the special applications and charging conditions.